Desiccating milk.



c. H. CAMPBELL. f

DESIGGATING MILK.

APPLICATION FILED NOV. 2, 1907.

Patented Jan. 16, 1912.

3 SHEETS-SHEET 1.

FIG;

INVENTOR w TNESSES:

C. H. CAMPBELL.

DESIGGATING MILK.

APPLIOATION FILED NOV. 2, 1907.

a SHEETSSHEET z.

ull

INVENTOR WITNESSES;

C. H. CAMPBELL. DESIGCATING- MILK.

APPLICATION FILED NOV. 2, 190v.

1,015,262. Patented Jan. 16, 1912.

3 SHEETS-SHEET 3.

"4A FIG. 5. M

' INVENTOR Wi NESSES; M

CHARLES n. CAMPBELL, or imw YORK, N. Y.

DESICCATING MILK.

Specification of Letters Patent.

Patented Jan. 16, 1912.

Application filed November 2, 1907. Serial No. 400,333.

whole milk or similar liquids containing small percentages of solids; and aims especially to effect a rapid elimination of the last remaining moisture in the product, and to obtain a light, loose product. To this end the milk, preferably after partial concentratio-n, is formed into a film, and the of milk A 15 'partially concentrated and inremaining moisture is extracted from it while in this shape, so that it is converted at once into a light powder which is substantially the same as when it was dissolved or suspended in the original milk. Preferably the original concentration is performed with the assistance'of heat below the coagulating point of albumen. The concentrated milk, before it loses any of the warmth of the first concentration (or, where this is, impracticable, after being subjected to a further warming), is then spread into a film, so that the warmth thereinhas a material effect in hastening the evaporation of the remaining moisture. The film may contain so little water as to permit its extraction by merely running it slowly through the open alr; but preferably it is run through an oven or drier in which either the heat or a current of air, dry and preferably warm, extracts the remaining moisture. The film is preferably carried upon a belt, and after the moisture is extracted the remaining powder is beaten, scraped, brushed,or'otherwise removed from the belt;

The accompanying drawings illustrate more or less diagrammatically several em-,

bodiments of the invention.

Figures 1 and 2 represent in vertical secout a process. Figs. 3, 4 and 5 are vertical sectional views illustrating modified mechanism for carrying out otherprocesses embodying the invention. Fig. 6 is a cross.- section, and Fig. 7 a longitudinal section, illustrating a mechanism for carrying out another process embodying the invention.

Referrin first to Figs. 1 and2, the body tion and in plan mechanism for carrying troduced into a vessel B and maintained at a suitable level therein. Through this vessel B runs a continuous belt C which is preferably of thin sheet steel or other metal, but which maybe of textile material or of any other suitable fabric. The belt C passes over suitable guide rollers D, E, to take up a coating of milk. Preferably a pressure roller G is arranged to engage the belt opposite the roller F so as to spread the milk in a very thin layer upon the belt, the existence or absence of the roller G, or its adjustment, being determined by the degree of preliminary concentration before the in-' troduction of the milk into the tank B. From the tank the belt runs very slowly, through an oven H of any-suitable construction, and typified as a simplei rectangular box with a gas heating pipe K underneath.

When the belt emerges from the oven H the moisture thereon will allhave been dissipated, and the solid matter will be left in the same finely divided and lightly distributed form as in the original milk, so that when it is replaced in water it will -be very readily dissolved or suspended in the same manner as originally. For the removal of the product from. the belt, a pair water jacket P by which the milk may be kept at any desired temperature. The vessel is covered, and provided with apipe Q through which compressed air may be introduced to force the milk in a thin stream through the v,slitted nozzle R upon thebelt C. The belt is carried in the direction of the arrow by means of rollers S, whichat the same time spread the milk as thinly as de-" sired. Or, if the milk is originally very thick, the film may be thinned in two stages,

using a. second pair of'rollers T, preferably adjustable as shown, for the purpose. Insteadof an inclosed oven the drymg may be effected by simply passingthe. belt over a gas pipe K provided with a suitable number The removal ofthe powder from the belt will be efl'ected by means of a brush U on the outer face; and, if a textile material through which the milk could pass, were used, a-second brush V would be provided on the inner side of the belt.

The first sta e of the process may be continued to a polnt beyond that at which the milk flows so readily as to pass through a nozzle in the manner of Fig. 3, or'to be.

' The doughy material may be fed by machinery to the mechanism which converts it into a film. For example,in Fig. 5, such a machine is shown in combination with a difl'erent style of film-forming apparatus.

A sort of pug-mill W expresses the thickly concentrated milk D between a pair ofbelts C C arranged to be pressed toward each other by means of rollers S. The belts carry a' certain quantity of milkbetween them, and stick to each other by reason of the nature of the milk, although the belts run from the rollers S to separated rollers X X.

. From the point of feed the belts run into an oven H heated by hot air admitted through the pipe a. The angle which the belts make with each other becomes so great that they pull apart and pass separately through the oven, the milk on each belt be-,

ingwell exposed to the heat. In the construction shown in this figure the belts are arranged to run twice (that is, on their forward and their backward lengths) through the oven, so that they will be in a somewhat heated condition when the milk is applied to them, and the desiccation will thus be hastened.

. Cream maybe mixed in an desired proportions in the original mil or may v be added to the milk after concentration and before spreading into a film. Instead of the oven or driers illustrated, there may be substituted a current of hot, dryair as described in patent of Joseph H. Campbell and myself No. 668,162. The brushes may be of steel or of fiber, or they may be sub-' stituted by scraping knives or the like. Where they are used on both sides of a belt they are preferably arranged opposite to each other so as to provide a support for the belt. Instead of the brushes or scrapers referred to, the dried product may be removed by simply beating or shaking the belt as by the outside beater Y and inside beaters Z (Fig. 5), this method having the advantage of avoiding lint or scrapings of metal or the like in the product. The film is not necessarily carried on a continuous belt. It may, for example, be formed upon sheets or the-like which are dipped in the tank of milk and are then hung in a drying room over night. The dipping of the sheets, or the application of milk to the belt or the like, may be repeated if necessar to obtain a film ofsufiicient thickness. rom such sheets the material may best be removed by beating or shaking. I

In using the dnumb of Figs. 6 and 7, the drum is rotated slowly, and milk of a suitable consistency introduced in such a quantity that in the rotation of the drum the milk will be spread out in a thin film over substantially the entire inner surface. A jet of dry warm air will be introduced through a nozzle 0 in such a manner as to maintain a drying atmosphere within the cylinder, the air preferably circulating in approximately the manner indicated by the spiral line. When substantially all the remaining moisture'hasbeen dried out. of the milk," it will be scraped or otherwise removed into the bottom of the cylinder, and

withdrawn through a hinged gate (1.

What I claim is The process of converting milk into a light powder which consists in preliminarily partially concentrating it and subsequently forming it into a film 'on a flexible traveling support, limiting the thickness of the filnr by a member at a substantially fixed distance from the support, extracting the remaining moisture from such. film, and removing-the product by heating or shaking said support.

In witness whereof, I have hereunto signed my name in the presence of two subscribing witnesses.

CHARLES H. CAMPBELL.

Witnesses:

. DOMINGO A. USINA, THEODORE T. SNELL. 

